97-04: Detection of supraventricular and ventricular arrhythmias by external loop recorder in patients with and without history of heart disease

Abstract

Background: external loop recorders (ELRs) yield higher arrhytmias detection than conventional multilead Holter monitoring, expecially if patients complain intermittent symptoms. In our centre we evaluated since January 2015 until January 2016, 31 patients with symptoms from possible arrhytmias or known heart disease who needed a risk stratification by ELR (Spiderflash-SORIN). The aim of the study was to verify usefulness of ELR in different clinical settings presenting in routine outpatient activity. Results: Age of our population ranged from 7 to 77 years old; main indication for ELR positioning was palpitations (14/31 pts, 45%), other other were:previous AIT/ischaemic events or Brugada Syndrome or previous AVNRT (2/31 for each cathegory), vertigo/syncope or pastAF (4/31 for both cathefory), ARVD or previous Ventricular tachycardia or previous atrial tachycardia (1/31 each one). 74% of them had normal basal ecg (23/31), 1 had postmyocardial infarction (postMI) ECG, 2 showed ectopic ventricular beats (EVB), 1 ectopic supraventricular beats (ESB), 2 were Brugada patients, 1 was an ARVD patient, 1 had RBBB. Spiderflash events recordings were critically evaluated from an electrophysiology technician and formally flagged as supraventricular or ventricular event by physician; a global amount of 41 diagnostic ecg strips were isolated, that allowed a diagnosis in 93% of patients altought a mismatch between symptom complained during ELR recording time and “real finding” was present: this means that ELR performed a diagnosis regardless patients'status. The mean recording time was 17,93 ± 4,58 days.We evaluated the events recorded automatically by ELR and those acquired after patients activation, and calculated the ratio between events confirmed by technician and physician to the whole events recorded. We found that automated records had a mean ratio “true to useless” higher than events triggered by symptoms: 0,28 ± 0,36 vs 0,12 ± 0,25 for automated and symptoms tracing respectively, p = 0,027; Fig1.Detection rate of ELR was similar for supraventricolar and ventricular events (p = 0,24) for each patient group. And when the indication to ELR was vertigo/syncope or palpitation both venticular and supraventricular events were found (p = 0,36); Tab1. We evaluated also the amount of event detected according to clinical status, and we found that patients prone to ventricular arrhythmias (Brugada patients, ARVD, VT history) had less probablity of supraventricular records than patients with history of supraventricular arrhythmias (past AF, pastAT, pastAVNRT, former AIT or thromboembolic event): patient with history of supraventricular tachycardias or ischaemic event had confirmed or newly diagnosed a supraventricular tachycardia, p = 0,035 (Chi squared for tables“true values” and “expected values”, DistXsq for probability calculation), Tab1. Conclusions: ELR-Spiderflash allowed a diagnosis of supraventricular tachycardia or ectopic vetricular beats in majority of patients who complained palpitations; perfomed a diagnosis of AF in patients wih history of AIT or systemic emboli; confirmed diagnosis of supraventricular tachycardias in those who had history of such arrhythmias; is useful in risk stratification in patients prome to ventricular events.